Mystery deepens over Gus Lamont's grandmother after she vanished from public view last year - as the missing boy's other grandma takes TV cameras inside the home where he disappeared 12 months ago

A surprise media blitz by Gus Lamont's grandmother Josie Murray has sparked speculation about Josie's wife Shannon who has not been seen in public since last November.On the eve of the first anniversary of Gus's disappearance, Josie Murray invited 7NEWS to Oak Park Station where he was last seen in South Australia's outback. It was her second interview with Seven - after earlier confronting the Daily Mail armed with a shotgun - and repeated her belief the four-year-old boy has been abducted.But Shannon was nowhere to be seen in the footage, and not even mentioned by name in the interview.She has not been spotted in public since she was photographed running errands in Jamestown on November 11 last year. Shannon was also not seen when Josie attended court on firearms charges earlier this year, with a family friend supporting Josie instead. According to police, Shannon was the last person to see Gus, who was said to be playing in a pile of sand next to the homestead, 300km north of Adelaide, on September 27.Despite extensive land and air searches, there has been no sign of the boy since.In February, police said they believed someone known to Gus may have killed him, deliberately or accidentally, before he was reported missing.Police said the suspect lived at Oak Park Station. Josie shows a 7NEWS Adelaide reporter where Gus was last seen by Shannon Shannon was last spotted in public on 11 November, running errands in Jamestown Four-year-old Gus vanished on 27 September last year - AFL grand final dayOn Monday, Josie, who said she is wrongly suspected by police of being involved in Gus' disappearance, insisted he 'had to have been taken - nothing else makes sense'.She said she was convinced Gus had been spirited out of the area and didn't believe he was 'still out here somewhere'.'No, I don't, at the moment,' she said. 'I don't think he's on the place.'I don't think he's near - dead or alive.' She said she still wanted 'to know the answer [to] what happened to him' before directing TV cameras to the pile of sand where Gus was playing on the afternoon he disappeared.'It brings me to tears that he's not here... Just down here. And then that was the last he was seen, and after that he just disappeared,' she said.It is the third time Josie has appeared in public without Shannon.Shannon describes her relationship with her former husband as 'business partners and close friends' since Josie's gender reassignment in 2009.Shannon's Adelaide lawyer James Caldicott, a partner at Caldicott + Isaacs, told the Daily Mail their client is 'under advice' from her legal team 'not to participate' in media appearances. Josie previously spoke to 7NEWS Spotlight in June, and has insisted she is innocent The little boy was living at his grandparents' Oak Park Station, south of YuntaHe insisted Shannon is cooperating with police, and was 'doing great... under the circumstances of what is obviously a family tragedy'. Mr Caldicott would not comment on whether Shannon remained at Oak Park Station with Josie.In June, Josie faced Adelaide Magistrate's Court, where she pleaded guilty to possessing an illegal gun silencer and was fined $10,500.Shannon did not attend court, instead writing a letter of support speaking to her 'exemplary character'.Since Gus's disappearance, the Murrays appear to have splintered. His devastated mother, Jessica, fled the station around January and is believed to be living in the family's Adelaide home with her younger son, Ronnie. She released a joint statement with Gus's father, estranged partner Joshua Lamont, in February.'Our lives have been shattered, and every moment without him is unbearable,' they said. Shannon, right, is pictured with Josh Lamont, Jess and Gus at the Yunta Race Club'We know someone out there may have information. If someone knows what happened, we are pleading with that person - or anyone who may have seen or heard anything - to please come forward.'It is not known whether Jessica remains in contact with her parents.At least 11 searches, including land, air, mineshaft and dam searches by police, the army, the SES and an Aboriginal tracker, have uncovered no clues.No charges have been laid and no arrests have been made in relation to Gus's disappearance.Josie's latest comments come weeks after South Australian police refused to confirm whether they still have a person of interest in the case.They also refused to confirm whether they have identified any other suspects.At the time, Josie's lawyer Andrew Ey told the Daily Mail: 'My client has always remained steadfast in her denial of being involved in Gus's disappearance.'Initially, police fiercely defended the family's request for privacy as they navigated the hunt for the boy. Shannon Murray pictured with her daughter Jessica as a baby in the South Australian outback There has been no sign of little Gus since he went missing a year agoBut in January, the working relationship between Josie and Shannon and Task Force Horizon investigators suddenly soured, with police later confirming the case had turned into a major crime investigation.Police said they had 'withdrawn' their cooperation with the investigation, which Shannon and Josie both denied through their separate lawyers.They seized electronics and vehicles for forensic testing, which yielded nothing of interest. Last month, SAPOL insisted that all three lines of inquiry remained under investigation: that Gus had wandered off and become lost, that he had been abducted or that a person known to him was involved in his disappearance.'Task Force Horizon has and will continue to investigate any and all information, including information provided by Gus's family, that could assist in identifying what has happened to Gus,' a spokesperson said.'As the investigation is ongoing it is not appropriate for SA Police to discuss specific aspects of the investigation that could compromise any potential future court proceedings.'READ MORE: Revealed: The last known sighting of Gus Lamont from anyone outside his family - hundreds of kilometres from Oak Park Station - as police zero in on a suspect: 'It's so sad'